Science: Electronic Senses

Rick Weiss
Washington Post Staff Writer
Monday, March 10, 2008; 1:00 PM

Washington Post science writer Rick Weiss was online Monday, March 10 at 1 p.m. ET to discuss new taste-testng technologies being developed to help judge the quality and tastiness of foods and beverages.

A transcript follows.


Rick Weiss: Hello readers, and thanks for joining in on the Monday Science chat. I'm all ears for your comments about noses and tongues, electronic or otherwise, as described in today's Science feature. But I am also happy to chat about any topics of scientific interest out there. I also encourage you all to give a good look at -- and say goodbye to -- today's "Science Notebook," the colection of short items that we post every Monday along with the Science feature. That Notebook is scheduled to be discontinued after this week as part of a redesign process that will gradually emerge.


New York, N.Y.: Smell has a large impact on how we taste things. What happens to our abilities to taste when you lose our ability to smell?

Rick Weiss: You are right. I've seen some estimates that as much as 80 percent of what we think of as "taste" is actually the contribution from the nose. Without smell, many things taste alike (apples and raw potatoes, for example). My wife, also a science writer, has a theory that this is not the worst affect of losing your sense of smell though. She says smell is also an integral part of what it takes to fall in love. Without it, it can be difficult to wholly bond to a mate. Anyone out there with little or no sense of smell and tales of woe (or otherwise) on the love front, please write in and add some data points to this idea.


Munich, Germany: "It takes that special human ability to come up with the hyperbole to really describe a wine."

Well it's nice to know that there's still a need for us human beings.

How closely connected is this food technology, molecular sensing, etc., with bomb detection technology? It sounds quite similar, with the exception that it's easier to describe a bomb than a wine.

Rick Weiss: Many smell-based systems are under development (and already in use) for finding landmines and other explosives. Bees have been trained to find explosives. And gambian pouched rats are really good at sniffing out landmines. When they find them, they sit down on them -- happily they don't weigh enough to set them off. Food smells are typically a lot more complex than the smell of a bomb (at least to us. Who knows what the rate thinks: Hmm this bomb has a hint of grapefruit and black pepper, with a pleasant lingering acidity at the end of the nose ...)so I don't see a day when bees will be rating Barberas for Wine Spectator magazine. But once scientists have figured out what the main odorants are in the food or drink of interest, the chemicals that play into people's tastes, it's just a matter of training the animal or machine to detect and measure them.


McLean, Va.: The problem I have with tasting technology is that taste is so subjective. Once upon a time blind taste tests in humans recommended something known as "New Coke," failing to recognize the strong emotional reactions people had to the original. How can a machine hope to take this subjectivity into account?

Rick Weiss: This is the crux of the machine-tasting problem. To the extent you can identify in advance universally agreed upon components of "good taste" or "good smell" for some food or beverage, you can make a machine that will identify those foods or drinks as such. And while yes, taste is subjective, there ARE some widely agreed upon standards for a lot of things. Usually, for example, when a wine expert says, "This is a great wine," most people will agree (partly of course because they want to agree with an expert). But there are what scientists call "top down" effects. A scientist told me the other day that if he gets me to smell some parmesan cheese and says the word "spaghetti," I will probably report that the cheese smells good. If he gives me the same whiff and says "dirty socks," I will probably say the smell is bad. Machines have a hard time dealing with that kind of human context, obviously.


Arlington, Va.: What implications does this have for the artificial flavor industry. Will we have the ability to develop a better fake grape flavor? Potato chip-flavored pretzels?

Rick Weiss: The synthetic flavor and scent industry is already huge. Think perfumes, for starters. Or onion-flavored chips ("Now, without onion!"). Or berry flavored kids medicine. Actually one of the biggest efforts in that industry right now is in pharmaceuticals. Most medicines, it turns out, taste bad by themselves. So there is a lot of money getting pumped into efforts to make pills taste good, or at least to neutralize the bad flavors of those meds. There is also a fair amount of research to suggest that certain tastes, and especially certain smells, have predictable effects on people's moods or even of their sense of how big a room is (note to real estate agents: useful during open-houses). If I were to whisper a stock tip to you (which I won't) it would not be "plastics." It would be "odors."


Takoma Park, Md.: How long before I can get a Star Trek food slot installed in my kitchen? You know, you say "Computer, a glass of chilled Tavel rose" and it appears, poof!

Rick Weiss: I already have that at home. She's called my wife.

But seriously, it will not be long (probably already on the market) before you can have a voice-actuated computer that relases certain scents into your room as needed. Something romantic for a Saturday night. Something stinky and dead-animalish when those pesky inlaws or neighbors show up.


Fairfax, Va.: Could this research help improve food safety? Could mechanical whiffers test meat before it's packaged to determine whether it's become a haven for germies...? My nose, and it's a big'un has detected many an off odor. Although, unfortunately it's a little too sensitive (someone drips a (tiny) spot of oil on the stove burner and I'm apt to holler from upstairs-IS THERE A FIRE?) I think I err too far on the side of safety and throw out too many foods. Your technology could identify which microbes were at work, couldn't they?

Rick Weiss: You are spot on, and sure enough, scientists are working on it already. There are certain odors -- we are all familiar with them; they come wafting out of those packages of chicken legs that sat around in the delivery truck too long -- that are specifically characteristic of spoiled meat or other "off" foods. Researchers are developing film coatings with nano-sensors and other kinds of sensors that can detect those odors and then, say, turn the food packaging red or organge to indicate spoilage. And you are right that this is especially a problem for those of us who are, well, let's just say it: aging. Sense of smell does decline with age. So it would be great to have food packages that tell our cataracted but still vaguely functioning eyes that, sheesh, this stuff is so far gone!


Rick Weiss: Thanks everybody for checking in.

And for all you e-noses and e-tongues out there: Keep it real!


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